A hybrid vehicle comprises a hybrid drive unit with an internal combustion engine and an electric machine. Connected between the hybrid drive unit of a hybrid vehicle and a drive output thereof is a transmission, namely an automatic or an automated transmission. Automatic transmissions are also called powershift transmissions.
When a hybrid vehicle that has been driving is brought to a standstill, it is already known from the prior art for a so-termed stop-start function of the internal combustion engine of the hybrid drive unit to stop the internal combustion engine when the motor vehicle is at rest and then to re-start the internal combustion engine, for example when the driver actuates the accelerator pedal. For example, this can happen when the motor vehicle stops at a traffic light or in a traffic jam.
In hybrid vehicles known from the prior art that have an automatic transmission, when the internal combustion engine is switched off or at rest the electric machine of the hybrid drive unit is coupled to the internal combustion engine and the transmission is shifted to neutral.
In hybrid vehicles known from the prior art that have an automated transmission, when the hybrid vehicle is at rest the internal combustion engine is decoupled from the electric machine of the hybrid drive unit and a starting gear is engaged in the transmission.
When the internal combustion engine is subsequently re-started, for example because the driver has actuated the accelerator pedal, the problem exists that the condition of the transmission and the condition of the clutch connected between the internal combustion engine and the electric machine of the hybrid drive unit may not be suitable for a starting mode of the motor vehicle that is to be used, so that before the internal combustion engine is actually started the transmission and the clutch connected between the internal combustion engine and the electric machine of the hybrid drive unit first have to be changed to a condition appropriate for the starting mode intended. This prolongs the time needed for starting the internal combustion engine, so the hybrid vehicle can then only move off after a time delay.